EP 0 314 540 B1 discloses in FIG. 4 a switchgear for a low-voltage circuit breaker having a switching shaft extending through a plurality of poles, each pole having a double contact mounted on the switching shaft. Owing to the rotative double contact, two series-connected arcs are enabled on opening of the switchgear. The series connection of the arcs effects higher current limiting. The known double contact has two parallel contact fingers in order to permit a higher current-carrying capacity of the double contact. The power loss and the associated heating of the contact fingers are reduced and the lift-off limit is raised. The contact fingers arranged in parallel are connected to the switching shaft by way of one tension spring per contact point. The tension spring arranged above and below the contact finger generates a contact force moment when the contacts are closed and always acts upon the two parallel contact fingers simultaneously by way of a coupling element. The installation space of the contact system is very large owing to the tension springs extending above and below.
DE 199 33 614 C1 discloses a contact system having a two-armed contact arm. On both sides of the contact arm there extend per end of the contact arm in each case two contact force springs. Owing to this arrangement, the installation space of the contact system is likewise very large. In order to construct a parallel arrangement of two or more contact arms for the purpose of a higher current-carrying capacity, the contact systems must be arranged next to one another, which increases the required installation space. The fixed contacts corresponding to the contact arms must also have a certain width in order to contact two or more parallel contact arms. Alternatively, a plurality of fixed contacts arranged in parallel must be used.
A further contact system is known, in which only one contact arm is formed (DE 102008007363 A1). The contact arm is acted upon by at least one contact force spring, but a mechanical coupling element is interposed between the contact force spring and the contact arm. The use of the coupling element serves to make the application of force symmetrical, but the construction of the contact system is made wider as a result.